With the advancement of the integrated circuits, more methods for manufacturing integrated circuit devices were explored. For example, in the formation of transistors, gate-first and gate-last methods were developed. In the gate-first methods, the gates of transistors are formed before the formation of source and drain regions. In the gate-last methods, dummy gates of transistors are formed, followed by the formation of source and drain regions. The dummy gates of the transistors are then removed and replaced with new gates, which may be metal gates.
Besides the formation of transistors, there are other devices such as transistors, capacitors, inductors, and the like, that may also be formed in the same chip as the transistors. The manufacturing processes of these devices need to be integrated with the manufacturing of transistors to develop a low-cost and a reliable manufacturing process.